LLE Review Quarterly Report (January-March 2002). Volume 90

Abstract

Price codes: Printed Copy A04Microfiche A01 Semyon Papernov, a scientist in the Optical Technology Group, uses a Digital Instruments Nanoscope I11 atomic force microscope (AFM) operated in contact mode to evaluate the morphology of 3w laser-damage features on a multilayer, quarter-wave-stack OMEGA transport HR coating made from HfO, and Si02 Surface mapping of damaged and undamaged sites on production witness pieces by atomic force microscopy has shown that nodular growth defects, long considered to be the dominant laser-damage driver in dielectric thin films, can remain unaffected under 35 1-nm irradiation conditions, while other defect-driving mechanisms dominate damage crater formation in the immediate vicinity of the nodules.This report was prepared as an account of work conducted by the Laboratory for Laser Energetics and sponsored by New York State Energy Research and Development Authority, the University of Rochester, the U.S. Department of Energy, and other agencies. Neither the above named sponsors, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or any other sponsor. Results reported in the LLE Review should not be taken as necessarily final results as they represent active research. The views and opinions of authors expressed herein do not necessarily state or reflect those of any of the above sponsoring entities.The work described in this volume includes current research at the Laboratory for Laser Energetics, which is supported by New York State Research and Development Authority, the University of Rochester, the U.S. In BriefThis volume of the LLE review, covering the period of January-March 1995, contains articles on the evaluation of the mechanism for laser damage in OMEGA UV multilayer coatings using a combination of conventional laser-damage characterization methods and atomic force microscopy; a dual-amplitude, fiber-coupled waveguide integrated-optic modulation device for generating temporally shaped optical pulses in OMEGA; a proposal for modifying the indirect-drive irradiation geometry of the National Ignition Facility (NIF) to provide the additional flexibility for performing direct-drive experiments; direct measurements of terminal-level lifetime in several different Nd:YLF laser media; an overview of the materials science issues, basic mechanisms, and potential device applications for light-emitting porous silicon; and a study of the time-dependent reflection and surface temperatures for laser-irradiated dental hard tissue at two CO2 laser wavelengths.Highlights of the research pre...